Protractor for a chalk line



FIG. 1 is a perspective view of a protractor for a chalk line, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is an another perspective view thereof; and,

FIG. 9 is an operational perspective view thereof, wherein the broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a protractor for a chalk line, as shown and described. 